Gameplay involves expanding from your team's starting Garrison to other sectors via wormholes (called alephs in-game). Players protect constructor drones that build new outposts for them to "spawn" from, techbases which allow new ships and equipment to be researched, and refineries which miner drones use to unload He3 (the primary source of credits).
Tactics revolve around securing safe mining areas, protecting your miners until you have a distinct technology advantage over the other team, and then destroying the enemy's remaining bases - much like a conventional Real-time strategy game. However, due to Allegiance's combination of RTS and space sim elements, some reviewers classify Allegiance in a genre of its own. Like an RTS there is a commander who builds bases and miners, harvests resources and comes up with strategies for defeating foes. Unlike an RTS where the commander has 100% control over all his units, in Allegiance all the ships are piloted by his teammates directly.
Depending on the technology path your Commander has chosen you might fly stealth craft, which are designed for destroying drones such as miners and constructors, or you might fly the interceptor, the king of defense and short-range dogfights. Destroying enemy bases requires the use of Bombers, and Scouts spot enemy movements, repair friendly vessels, and can even deploy minefields to devastate and delay an enemy attack.
A typical game lasts between thirty and forty-five minutes, although games of more than two hours in length are not uncommon.
Allegiance has a reputation for not being an easy game to learn, even with its simplified flight model. It has a complex control scheme and a heavy focus on teamwork, tactics and player co-ordination. One must know your ordnance and, more importantly, know where to be and what one should be doing there (aka Situational Awareness). Given the enormous amount of factors to reckon with, it takes the average player somewhere between three and six months to firmly grasp the game.
The game includes 7 training missions - 6 original ones that were produced by Microsoft, and 1 that was created after the game went shared-source. These tutorials teach you all the controls of the game such as how to target enemies, pilot your ship, communicate with teammates, etc.
However these tutorials teach you almost nothing about how to play a game of Allegiance - what the objectives are, where you are supposed to go, how to help your teammates, etc. For this purpose the community have created their own web-based training program. Without their efforts, the 3-6 month learning period would be much longer.
- Cadet I - this is designed for people that have just downloaded the game. It takes you from raw recruit to someone that can be useful in most situations. It contains enough information and strategy guides that 3 weeks are allocated for users to get through it comfortably.
- Cadet II - designed for people completing Cadet I. It takes you from a novice to a decent player. It expands on all the topics covered in Cadet I and introduces many new topics, such as advice on piloting the medium and heavy class ships. It is an 8 week course.